Content/information search system

ABSTRACT

An information search system that enables efficient collection of information and support of formation of groups which people who share a same interest can join over a network. This system includes an intermediate server and a central server, wherein the intermediate server retains indexes for searching the content database on the central server. Users issue a search request to the intermediate server and search results are returned and recorded on the intermediate server as a search history. The search history is shared by users and used as references from which retrievable content can be selected.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an information search system forsearching for information/content that is distributed over a network.

2. Description of Related Art

The development of the Internet has made it possible for many people toenjoy collecting information in a field of their interest via thisglobal network. In the Internet environment, however, web servers andthe like are separately provided, and, consequently, often informationin a field is widely distributed and cannot be efficiently obtained. Inorder to collect sufficient information, some people who share the sameinterest form a Closed Interest Group (CIG) in which quite highlyspecialized information is exchanged.

However, because the CIG uses a Bulletin Board System (BBS), informationis accumulated through the process of exchanging a message and areplies. Although fragmentary information can be collected, the CIGsystem is not suitable for intensively obtaining a great deal ofinformation.

With an information search or collection system based on a conventionalBBS, it is difficult for a seeker to efficiently collect informationabout a particular object of interest. In such a system, the only way tofind out whether another person in the CIG shares your interest is toread messages from the person and form an opinion based on thatinformation. For example, if there exists a CIG for the Japanesechess-like game of shogi, its members may be fond of different forms oftactical deployment of the shogi pieces. For example, there is no wayfor a member who is fond of one style of play, such as that known as“shiken-bisha” to find other members who also like “shiken-bisha.”Although conventional BBS systems allow users to find others who sharethe same general interests, such as “shogi”, in those systems it isrelatively difficult to find among participants another user sharing aninterest in a rather minor specialized field. Therefore, many users aredissatisfied with such systems.

SUMMARY OF THE INVENTION

The present invention has been devised to address the abovecircumstances of information search. The object of the present inventionis to provide an information search system that enables efficientcollection of information with considerations of forming groups whichpeople who share a same interest can join through a network.

In order to solve the above-described problems of previous informationsearch or collection systems based on the BBS system, the presentinvention provides, in one aspect, an information search system forproviding user terminals with a search service for content on a centralserver including a database in which content is stored (the databasewill be referred to as a content database hereinafter). This informationsearch system includes an intermediate server located between thecentral server and the user terminals. The intermediate server comprisesdevice for receiving a user search request from a user terminal,searching the content database on said central server on behalf of theuser terminal, and presenting search results to the user terminal; anddevice for recording and retaining the search results returned by thesearch request as user search history, wherein the above search resultsand the results of past searches requested by the user are recordedtogether. The information search system makes available to users theuser search history so that the search history is shared across theusers and used for support of the users' search operations.

In another aspect, the present invention provides an information searchsystem for providing user terminals with a service for searching contentstored on a central server including a content database, the informationsearch system including a plurality of intermediate servers locatedbetween the central server and the user terminals and specialized forpredetermined fields of user interest. Each of the plurality ofintermediate servers comprises device for receiving a user searchrequest from a user terminal, searching the content database on saidcentral server on behalf of the user terminal, and presenting searchresults to the user terminal; and device for recording and retaining thesearch results returned by the search request as a user search history,wherein the above search results and the results of past searches byrequest of the user are recorded together. Each of the user terminalsretains the identifier of an intermediate server selected by its user asthe one to which a search request is issued, wherein the user can selectanother intermediate server in place of the intermediate server. Theinformation search system provides the user search history to otherusers so that the search history is shared by users and used for supportof user search operations.

In a further aspect, the present invention provides an intermediateserver located between a central server on which is stored a contentdatabase and user terminals for accessing the intermediate server toobtain content stored on said central server. The intermediate servercomprises device for receiving a search request from a user terminaloperated by a user, searching the content database on said centralserver on behalf of the user terminal, and presenting search results tothe user terminal; and device for recording and retaining the searchresults returned by the search request as search history per user,wherein the search results and the results of past searches performed atthe request of the user are recorded together. The intermediate servermakes the user search history per available to users so that the searchhistory can be shared by users and used to support user searchoperations.

An advantage of the invention is that the user search history is sharedacross the users in this way and this allows the users to search forcontent in the field of interest while referring to the search history.Reference to the search history makes it easier for a user to otherusers who have the same interest as the user and can be used for formingclubs or groups Internet.

In yet another aspect, the present invention provides intermediateservers located between a central server including a content databaseand user terminals that access one of the intermediate servers toretrieve content stored on said central server, each of saidintermediate serves being specialized for a fields of user interestregarding content. Each intermediate server comprises device forreceiving a search request from a user terminal, searching contentfalling within its specialized field in the content database on saidcentral server on behalf of the user terminal, and presenting searchresults to the user terminal; device for recording and retaining thesearch results returned by the search request as a user search history,wherein said search results and the results of past searches by requestof the user are recorded together; device for retaining informationabout other intermediate servers' specialized fields; and device forsearching other intermediate servers with a field key and presentingsearch results to the user terminal. The intermediate servers providethe user search history to users so that the search history can beshared by users to support their search operations.

The foregoing intermediate server may further comprise device forreceiving a request to retrieve content from a user terminal, retrievingthe content from the central server, and distributing the content to theuser terminal. When the user has issued the request to get content thatwas selected by making reference to search history of another user,preferably, the intermediate server executes a process of rewarding theother user. This would induce users to make their search history open.

Furthermore, the search history includes information about when thesearch was executed. When a predetermined period has elapsed after thetime when the search was executed, it is preferable to delete the searchhistory.

Furthermore, the search history may include an evaluation by anotheruser who referenced it. It is preferable that the evaluation informationbe in the processing for presenting the search history.

In a still further aspect of the present invention, the presentinvention provides an information search method for searching a contentdatabase on a central server by user request. The information searchmethod comprises the steps of receiving a search request from a user;searching the content database on the central server; presenting searchresults to the user; and recording and retaining the search resultsreturned by the search request as a user search history, wherein theabove search results and the results of past searches by request of theuser are recorded together. In this method, the user search history isrendered to users so as to be shared across the users and used forsupport of the users' search operations.

In yet another aspect, the present invention provides acomputer-readable medium having an information search program storedthereon, the information search program for searching contents by userrequest, using a content database. This program comprises a module forcausing the computer to execute the steps of receiving a search requestfrom a user, searching the content database on said central server, andpresenting search results to the user; and a module for causing thecomputer to execute the step of recording and retaining the searchresults returned by the search request as a user search history, whereinthe above search results and the results of past searches by request ofthe user are recorded together. Through this program, the user searchhistory is rendered to users so as to be shared across the users andused for support of the users' search operations.

Preferably, a predetermined amount of money should be set as a limit forthe rewards to be given to another user, and, when said predeterminedamount is exceeded, no further reward is given.

In a further aspect, the present invention provides a central serverincluding a content database from which content is distributed to userterminals by request and connecting to an intermediate server locatedbetween the central server and the user terminals. The intermediateserver receives a search request of a user from a user terminal,searches the content database on said central server on behalf of theuser terminal, presents search results to the user terminal, and recordsthe search results as search history. The central server comprisesdevice which, when a first user has performed a content searchoperation, generates key data to be attached to the search historyrecord of the first user and retains the key data liked with the firstuser identifying information; device for sending the thus generated keydata to the first user's terminal device; and device which, when asecond user gets content selected by making reference to the searchhistory record of the first user, identifies the first user by verifyingmatching between the key data included in the referenced search historyrecord of the first user and the key data retained. The first user'sterminal device encrypts the key data with the first user's pre-assignedprivate key and the encrypted key data is incorporated into the searchhistory record at the intermediate server. When the second user makesreference to the search history record, the encrypted key data isfurther encrypted with the second user's pre-assigned private key andthe double encrypted key data is sent to the central server. Then, theabove device for identifying the first user decrypts the doubleencrypted key data with the first user's and second user's private keysand, using the thus reproduced key data, verifies key data matching.

In a still further aspect, the present invention provides a method ofrewarding a searcher, using a central server including a contentdatabase from which content is distributed to user terminals by request.The central server connects to an intermediate server located betweenthe central server and the user terminals. The intermediate serverreceives a search request from a user terminal of a user, searches thecontent database on said central server on behalf of the user terminal,presents search results to the user terminal, and records the searchresults as search history. The above method comprises a step in which,when a first user has performed a content search operation, key data tobe attached to the search history record of the first user is generatedand retained, linked with the first user identifying information; a stepof sending the generated key data to the first user's terminal device;and a step in which, when a second user gets content selected by makingreference to the search history record of the first user, the first useris identified by verifying matching between the key data included in thereferenced search history record of the first user and the key dataretained. The first user's terminal device encrypts the key data withthe first user's pre-assigned private key and the encrypted key data isincorporated into the search history record at the intermediate server.When the second user makes reference to the search history record, theencrypted key data is further encrypted with the second user'spre-assigned private key and the double encrypted key data is sent tothe central server. The above step in which the first user is identifiedmay comprises steps of decrypting the double encrypted key data with thefirst user's and second user's private keys and verifying key datamatching, using the thus reproduced key data. In this method, a rewardis credited to the thus-identified first user.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structural block diagram of an information search systemconfigured in accordance with a preferred embodiment of the presentinvention.

FIG. 2 illustrates an example search history.

FIG. 3 shows an example of display of a search history on a userterminal.

FIG. 4 illustrates examples of category classification and codeassignment.

FIG. 5 shows an example dialog box for user registration in a graphicaluser interface (GUI) for the preferred embodiment of the invention.

FIG. 6 is a process flow diagram illustrating the operation of theinformation search system of the preferred embodiment of the invention.

FIG. 7 shows an example login window in a GUI for the preferredembodiment of the invention.

FIG. 8 shows an example search window in a GUI for the preferredembodiment of the invention.

FIG. 9 shows an example past search results window in a GUI for thepreferred embodiment of the invention.

FIG. 10 shows an example past hits list window in a GUI for thepreferred embodiment of the invention.

FIG. 11 shows an example history search window in a GUI for thepreferred embodiment of the invention.

FIG. 12 shows an example history records window in a GUI for thepreferred embodiment of the invention.

FIG. 13 shows another example past search results window as a GUI in aGUI for the preferred embodiment of the invention.

FIG. 14 shows another example history search window in a GUI for thepreferred embodiment of the invention.

FIG. 15 shows an example window showing past searches by other users,used in a GUI for the preferred embodiment of the invention.

FIG. 16 shows another example search history window in a GUI for thepreferred embodiment of the invention.

FIG. 17 shows an example comments list window in a GUI for the preferredembodiment of the invention.

FIG. 18A illustrates an example of determining an amount of money to begiven to a user.

FIG. 18B illustrates another example an amount of money to be given to auser.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A preferred embodiment of the present invention will now be describedhereinafter with reference to the accompanying drawings. Referring toFIG. 1, an information search system configured in accordance with apreferred embodiment of the present invention essentially consists of acentral server 1, user terminals 2, and one or more intermediate servers3. The central server 1 comprises a content database 11 on which contenthas been stored, a control unit 12, and a communications unit 13. Theintermediate server 3 comprises a communications unit 31, control unit32, storage 33, and clock 34. Any of the central server 1, userterminals 2, and intermediate servers 3 may be a computer that reads andexecutes a program stored on a computer-readable recording mediumincluding a magneto-optic (MO) disc, CD-ROM, hard disc, etc.

The central server 1 is embodied in, for example, a server computer thatruns under the management of an information distributor. Data contentsupplied by the information distributor is stored in the contentdatabase 11. In response to a request from an intermediate server 3received by the communications unit 13, the control unit 12 distributescontent retrieved from the content database 11 to the intermediateserver. When the content database 11 is updated, the control unit 12notifies the intermediate server(s) 3 of the update information. Onenoticeable feature of the present preferred embodiment is that thecontrol unit 12 authenticates the intermediate server 3 when it acceptsrequest therefrom.

Furthermore, the control unit 12 charges for the content distributed toan intermediate server 3 and notifies the intermediate server 3 of thecharge. While only one central server 1 is shown in FIG. 1, a pluralityof central servers 1 may be provided.

The communications unit 13 connects to a network, receives requesttransmitted across the network 13 from an intermediate server 3, andoutputs the request to the control unit 12. The communications unit 13also transmits a diversity of data, according to the instructions issuedfrom the control unit 12.

A user terminal 2 is, for example, a general personal computer thatconnects to the intermediate server 3 via the network. In the userterminal 2, software for requesting the intermediate server 3 to executea search and receiving search results and software for viewing contentdata are installed.

An intermediate server 3 can also be embodied in a general servercomputer wherein a communications unit 31 transmits and receives dataover the network according to instructions issued from a control unit32. The control unit 32 essentially executes the following: a process ofgenerating and managing index information for searching the contentdatabase on the central server 1 (index management process); a processof searching for content data requested in a search request from a user(search process); a process of retrieving content data on behalf of theuser and transferring it to the user (content retrieval and relayingprocess); a process of creating and storing a user-specific searchhistory (search history storing process); and a process of renderingsearch history to be shared by users (search history rendering process).The above processes are described in detail further below. Informationstored in the storage 33 includes indexes, user authentication data, anduser-specific search history. The clock 34 keeps date and time in realtime.

The processes that are executed by the control unit 32 of anintermediate server 3 will now be explained, beginning with the indexmanagement process.

[Index Management Process]

The control unit 32 generates indexes for searching the content databaseon the central server 1 and stores these in the storage 33. When thecontent database on the central server 1 is updated, the control unit 32updates the indexes based on update information received from thecentral server 1. Because the indexes can be obtained by indexing ascommonly practiced in the art, further explanation thereof is not made.

Because multiple intermediate servers may be provided in the system ofthe present embodiment, the central server 1 has a list of the address(es) of intermediate server(s) 3 to which the content database updateinformation is sent.

[User Registration]

A user must first register with any intermediate server. The controlunit 32 uses user registration data to authenticate a user. Using a userregistration window of graphical user interface (GUI), a user enters hisor her nickname (user ID) and password and chooses whether to havesearch history recorded by default or whether to make search historyopen by default. The control unit 32 stores the input user informationon the storage 33.

[Search Process]

When an intermediate server receives a search request from a userterminal 2, its control unit 32 send a request for the user ID andpassword. The control unit 32 receives the user ID and password enteredby the user and compares them with the pre-registered user ID andpassword, thereby authenticating the user. When it has been verifiedthat the user issuing the request is the registered user as the resultof authentication, the search process begins.

In the search process, the intermediate server's control unit receivesinput search criteria (such as keywords), searches the indexes stored inthe storage according to the search criteria, and returns search resultsto the user terminal 2.

Specifically, the control unit 32 can implement this process bypresenting a GUI web page to the user. The authenticated user ID isembedded in the web page, which displays a keyword input field and asearch button. When the user clicks the search button, the intermediateserver receives the embedded user ID and the keyword(s) as a query, andthe control unit executes the program for searching for content matchingthe keyword(s) (search criteria).

In this way, the intermediate server having the indexes for searchingthe content database, rather than of the central server 1, executes thesearch. Therefore, the intermediate server can execute a search withoutdisclosing search history to the central server 1. In other words, thissearch manner is useful for enhancing security in such a way that, forexample, a firewall and a proxy server can be provided between theintermediate server 3 and the central server 1. By doing so, additionalsecurity can be provided to a level such there is little realistic fearthat another organization would be able to illegally reference thesearch history. This function of the intermediate server 3 isparticularly desirable when a search relates to information, such aspatent information or intellectual property, for which secrecy isdesired.

[Search History Storing Process]

When the intermediate server presents search results to the user, theuser is asked whether or not the search results should be recorded assearch history data. When the intermediate server is requested to recordthe search results as search history data, the control unit 32 promptsthe user to enter character strings (comments) explaining the goal ofthe search (the results desired by the user). These comments differ fromkeywords and consist of words in which the user subjectively states whatkind of information he or she seeks; for example, “Through this search,I obtained shogi diagrams for recent professional matches in which‘shiken-bisha’ was used; there were only a small number of hits, but theresults can be used for reference.” On the other hand, as the criteriafor a search that can actually be employed, the user should specify aspecific period rather than a relative term like “lately” and shouldonly use discrete and objective words such as “shiken-bisha” and “shogidiagram”.

Then, the control unit 32 executes the search history filing process inwhich the user ID by which the search request user is identified, thecomments, the search criteria, and the search results are stored in thestorage 33 as one data set. Search history data records are accumulatedin the storage 33. A search history record consists of entries such as,for example, those that are shown, in FIG. 2. In this example, theentries consist of a user ID (history record registrant name) which isused as the key of the record, contact to the user (registrant) (A),specified search criteria (B), search results (C), time when the searchwas executed (D) according to the clock 34, evaluation (E), and comments(F). The possible contact to the registrant may be an e-mail address,the URL of a web site/homepage, or an Internet Relay Chat (IRC)identifier for the registrant of the search history record. Prior toprocessing, the evaluation is set at an initial value, for example, “0.”

In this preferred embodiment, after executing a search, the intermediateserver prompts the user to input comments which are recorded as a partof the history record of the search. This step is intended to collectinformation reflecting the actual circumstances of user search requestactivity. Often, users will refine search criteria and input a number ofsearch requests before obtaining desired search results. During thisprocess, the user's interest may change and the user may begin to seek adifferent type of information. Such evolution of search criteria can bereflected in the search history record.

[Search History Rendering Process]

Another notable feature of the present preferred embodiment is that thecontrol unit 32 of an intermediate server makes the accumulated searchhistory records available to a user when the user requests a search sothat the search history information can be shared by users. The controlunit 32 analyzes the comments entered with a search request, retrievessearch history records related to the comments from the storage, andprovides these to the user. Analysis of the comments and retrieval ofsearch history records can be carried out using any suitable, commonlyknown comparison manner for finding analogous phrases.

FIG. 3 exemplifies presentation of search history records. Searchhistory records of a registrant are shown in the display area (P) withinwhich the records (Q) of the registrant are listed. Each search historyrecord (q1, q2, . . . qn) includes data on the subject of the search andthe state of the search results (the number of “hits” of searchedcontent titles) with the embedded link to further information for therecord. When the viewer clicks the hypertext link, further informationof the record is displayed, such as the registrant name as the key, thecontact to the registrant, the specified conditions of the search,search results, time when the search was executed, evaluation, andcomments. In the name string of the registrant of a history record inFIG. 3, the link to the contact to the registrant is embedded. If, forexample, the registrant's e-mail address is embedded as the contact,when the viewer clicks at the registrant name, the GUI window forsending e-mail to the registrant appears.

The control unit 32 obtains the evaluation of a rendered search historyrecord from the user (viewer of the search history) and updates theevaluation included in the record. The referential usefulness of therecord is graded in, for example, five levels for which values of “2,”“+1,” “0, ” “−1,” and “−2” are assigned respectively. When the viewerspecifies one of the levels, the control unit updates the currentevaluation by adding the value corresponding to the level. Moreover, thecontrol unit 32 deletes search history records older than a certain timefrom which predetermined days has passed out of the storage 33 byreferring to the clock 34.

Furthermore, the user can attach a bookmark to a search history record.When the user attaches their bookmark to a search history record, thecontrol unit 32 links the viewer name to the registrant name and storesthis link as the bookmark when again storing the record in the storage.Upon receiving a user request to reference the bookmark, the controlunit reads the registrant name linked with the viewer from the storedbookmark. Using the registrant name as the key, the control unitretrieves that user's search history records from the storage 33. Byusing bookmarks, a user can again reference the search history of aspecific registrant by simple operation. The user can search for contentusing the search history of a previous searcher sharing an interest inthe same topic. By doing so, the viewer can more efficiently collectinformation.

[Content Retrieval and Relaying Process]

In the content retrieval and relaying process, when the control unit 32of an intermediate server receives a request for content selected by theuser from the content list presented as a search result, it sends to thecentral server 1 a request for the selected content. The control unit 32then receives the content distributed in response to the request andtransfers it to the user terminal 2. In this way, because theintermediate server 3 retrieves content from the central server 1 onbehalf of the user terminal 2, the central server 1 authenticates theintermediate server 3 instead of authenticating the user. Therefore,user management to be exercised by the central server 1 is greatlysimplified. The control unit also calculates a charge for the contentdistributed to each user.

A user may select content, taking advantage of the search resultsincluded in the search history referenced by the user, and issue to anintermediate server a request for that content. Upon receiving such arequest, the control unit 32 sends the central server 1 the identifierof the user who issued the request and of the selected content, receivesthe requested content in response to the request, and transfers thecontent to the user terminal 2. Moreover, the control unit 32 creditsthe registrant of the search history referenced by the user with apredetermined reward. The reward may be, for example, that the controlunit 32 discounts the charges payable by the registrant by a certainamount. The advantage may be embodied as a discount of a predeterminedsize from future content charges to that registrant or a cash payment tothe registrant.

[Providing Intermediate Servers]

Because an intermediate server 3 executes between a user and the centralserver 1 processes as described above, the processing load on theintermediate server 3 may be great. It is preferable to provide separateintermediate servers 3 specialized for the fields of users' interests;that is, providing a plurality of intermediate servers 3, including, forexample, an intermediate server 3 for handling access by usersinterested in “shogi” and another intermediate server 3 for handlingaccess by users interested in movies. A user selects an intermediateserver 3 according to the field of his or her interest and registershits or her authentication information with that intermediate server 3.

It is also preferable to provide specialized intermediate servers fordifferent categories within one field of interest, such as, for example,music may divided into a plurality of categories (classical, jazz,popular, etc.).

In this case, content is stored in the database on the central server 1,preferably, each content file including category information as itsbibliographic information, thereby enabling the central server 1, byreferring to the category information, to provide the appropriateintermediate server(s) 3 with category specific content updates.

When a new intermediate server 3 is connected to the system, theprovider declares the categories (fields of interest) with which the newintermediate server 3 will communicate with the central server 1.Specifically, this declaration is a message of notice of a category sentto the central server 1. Preferably, the central server 1 thenbroadcasts the categories of the new intermediate server 3 and itsreference information (host name, URL, IP address, etc) to otherintermediate servers 3 to which the central server 1 sends updateinformation. Thereby, each intermediate server 3 stores the categoryinformation for other intermediate servers 3 and this categoryinformation can be provided when a user is seeking an intermediateserver 3 appropriate for his or her field of interest. It is preferableto predefine category codes and supply them as the category information.

Specifically, a user must specify keywords indicating the field of hisor her interest as conditions of a search and send the keywords to anyintermediate server 3, so that the user can search out a suitableintermediate server out of other intermediate servers 3 and obtain itsreference information such as the host name of intermediate server 3located by that search request.

It is preferable that the category specification codes be defined in ahierarchy which accounts for categories within a field of interest, asis the case in music. An example code hierarchy is illustrated in FIG.4, wherein the top hierarchy is “Music”, the second hierarchy includespopular music “A000” and jazz“B000”, the third hierarchy including“A100” standing for “Japanese popular” under the “popular” category(“Japanese popular” is a subcategory of “pops”). If the category of anintermediate server 3 is listed as “Music” it handles all music genres.If its category is “A000”, it handles “popular” including, for example,both “American” and “Japanese”. However, if the category is “A100”, theserver only deals with “Japanese pops”.

When a plurality of specialized intermediate servers 3 are provided asdescribed above, a user must select an intermediate server 3 andreference information (host name, URL, etc.) to which the user terminalconnects by default and a default category (field of user interest) inwhich a search is executed when performing user registration. Moreover,the user must choose whether reference other intermediate servers 3. Forshared data management of user registration, it is also possible to usea network database, for example, the Network Information Service Plus(NIS +) (registered trademark) database.

While one intermediate server 3 is assigned for one category or userinterest in the above description, it is also possible that oneintermediate server 3 executes processing to accommodate a plurality ofcategories or fields. This can be implemented by running a plurality ofsoftware programs on one server.

It is preferable to allow a user to change at least an intermediateserver 3 and reference information as well as the category among theitems set during user registration. Thereby, the user can change theintermediate server setting appropriately according to their evolvinginterests. It would be convenient for users that all settings entered atuser registration except user name (user ID) be changeable later.

[Registering a Group with an Intermediate Server]

It is also possible to register a group consisting of a plurality ofusers with an intermediate server when user registration is performed.In this case, as the contact to the user (search history recordregistrant), either the e-mail address of a representative of a group orthe e-mail addresses of all members of the group may be specified. Whenusers are registered as the members of a group in this way, any rewardsprovided are awarded to the group. If, for example, the reward is a cashremuneration, the reward may be preferably shared by the members of thegroup.

[Current Popularity Considerations]

The control unit 32 of an intermediate server 3 records numerical dataon reference to search history and content titles distributed to usersand calculates the distribution of the numerical data for everypredetermined period. The control unit analyzes the trend in frequencyat which a seeker-specific search history has been referenced and acontent title has been distributed. Based on this analysis, the controlunit creates a web page containing search history records which show agreatly increasing rate of access based on the above numerical data andprovides this to users by request. By providing such web pages on whichsearch history and content accessed by a lot of people for a shortperiod, for example, content such as information about a new song of apopular singer can be highlighted, and usability can be enhanced. Anintermediate server 3 analyzes the numerical data for each category andfield of user interest in order to present highlights in each categoryand field to users. In this way, information about current popularitycan be provided.

[Operation]

The operation of the information search system of the preferredembodiment will now be explained. A user must first register with anintermediate server 3, which may be one of a plurality of intermediateservers. Specifically, a user accesses a web page for user registration,such as the GUI window shown in FIG. 5, and enters user ID, defaultserver, and default category into appropriate fields, and chooseswhether to have search history recorded by default, whether to makesearch history open or closed, and whether to use reference to otherservers.

Once a user has registered with an intermediate server, the user canopen his or her search history and can reference search history of otherusers. Referring to FIG. 6 wherein system operation is illustrated foran example wherein the search history of a first user (search historyrecord registrant) is referenced by a second user (viewer), theillustrative operation will be explained below.

Assuming that intermediate servers 3 are provided separately for fieldsof user interests and the following explanation focuses on a “Music”server. The intermediate server 3 provided for music information searchenables searches on a category-specific basis.

A content distributor supplies content to the central server 1 on whichthe content is stored in a database (S1). When the content database isupdated, the intermediate server gives notice of update to theintermediate server 3 (S2). The intermediate server 3 updates theindexes for searching the database.

The first user as a producer of search history records accesses theintermediate server 3 for authentication. The first user enters user IDon a login window which is illustrated in FIG. 8. The first user logsinto the intermediate server 3 (S3) and enters conditions of a search ona search window such as that shown in FIG. 8. When the user issues asearch request, the intermediate server executes a search (S4). In theillustrative window shown in FIG. 8, category “classical” is selected(P), and thus a search about classical music is executed.

A search history is displayed on a window such as that illustrated inFIG. 9, wherein search identifiers (I), search criteria (C), and hitsobtained as search results (T) are tabulated. The search identifiers (I)can be used as search criteria. In the present example, a search withkeyword “Bach” is executed and as shown on the first line of the tableshown in FIG. 9, that is, the search with identifier “1” and criteria“Bach”, returned 54,649 hits. When condition “1 * Instrumental Music”was added to the search 1, a search for information related to twokeywords “Bach” and “Instrumental Music” was executed. A link to awindow (FIG. 10) for listing the search results of the hits is embeddedin the field of hits (T). By clicking on this link, the user can viewthe search results. The appearance of the search results window differsaccording to the characteristics of information searched out. In theexample shown in FIG. 10, links for activating audition and download areprovided with the search results.

In example of the present embodiment, “Delete” links are attached to theitems of search history as shown in FIG. 9. Using these links, searchhistories that regarded as inappropriate can be deleted by a user whohas chosen to have search history recorded by default. If the user chosenot to have search history recorded at user registration, the functionof these links is reversed and a “Record (history)” button replaces the“Delete” button.

When desired search results are obtained, the first user clicks theterminate button to terminate the search operation, enters informationsuch as comment, and sends the intermediate server a request to recordthe results with the comment as search history (S5). The intermediateserver 3 stores search history records in time sequence (S6), eachrecord consisting of entries: ID of the user/registrant, contact, theidentifier of the search recorded as search history, search criteria(including a category), search results, and comment. The intermediateserver 3 sets a flag to each search history record. Among a series ofsearch history records, this flag is set at “1” for the first record,“2” for the last record of the search results obtained immediatelybefore terminating the search operation, and “0” for other records.

Usually, search history of a searcher, stored for one search operation,contains a series of search history records (a set of records). Afteraccessing the intermediate server 3, the user often attempts a number ofconsecutive searches, changing the search criteria until the desiredresults are obtained. Thus, the flags are used to define the range ofone search operation performed by a seeker. Specifically, referring tothe flags of search history records in time sequence, the intermediateserver 3 regards search history records between the record flagged “1”and the record flagged “2” as a series of records. If single searchattempt returns desired search results, to the search history recordthereof is assigned a flag “1”, can be a flag “2” indicating it to bethe most recent search. By referencing the flags assigned to searchhistory records, a flag sequence “1,” “0” . . . , “2,” “1,” “1” or “1,”“0” . . . , “2,” “2,” “1” can detected. The “2” flag followed by flag“2”, or the “1” flag followed by flag “1”, that is, two successiveidentical flags, indicates the end of a series of search history recordsof one search operation and these records can be retrieved in a block.

If the search criteria specified in a search history record includereference to the search criteria of another record (the criteriaincluding the search identifier of the reference record), the searchhistory record preferably includes the search identifier of thereference record as a “parent search identifier”. Similarly, the searchhistory record having the search criteria referenced by another recordincludes the search identifier of the record referencing the earlierrecord as a “child search identifier”. For example, when a first historyrecord of a search executed with search criteria “Bach” (searchidentifier “1”) and a second history record of another search executedwith search criteria “1 * Instrumental Music” (search identifier “2”)that makes reference to the search criteria in the first record, thefirst record with search identifier “1” includes a child searchidentifier “2” and the second record with search identifier “2” includesa parent search identifier “1.”

When the first user selects desired content out of his or her searchresults presented on the window shown in FIG. 10 and issues a requestfor retrieval of the content (S7), the intermediate server 3 sends tothe central server 1 a request for retrieval of the content on behalf ofthe user (S8). The central server 1 authenticates the intermediateserver 3 and distributes the content to the intermediate server 3 (S9).The intermediate server 3 transfers the retrieved content to the userterminal 2 of the first user (S10) and charges the first user for thecontent (S11). The central server 1 simultaneously notifies theintermediate server 3 of the charge for the content (S12). Payment iscompleted such that the intermediate server 3 collects from each userthe charges for the content they receive through the intermediate server3, and forwards the thus collected charges to the central server 1.Thus, information identifying the users that received the content is nottransferred to the central server 1.

When a second user is authenticated by and logs onto the intermediateserver 3 (S13), that user can issues a request to reference searchhistory. For example, this request may be input by clicking the “HistorySearch” button on a search window such as that shown in FIG. 8. When the“History Search” button is clicked, the intermediate server 3 presents aGUI window (web page) such as that shown in FIG. 11 to the user. Anoticeable feature of the GUI window shown in FIG. 11 is that allows theuser to specify a search range (X). Specifically, the window allows theuser to select reference to the history of his or her past searches (“mysearch history only”), reference to search history under the category,or searching all search history records.

The second user enters conditions of a search and issues a request tosearch through open search history records. Returned search results areshown with search identifiers (Y) in the same manner as for a contentsearch, so that a search identifier can be specified and included insearch criteria. As the result of the history search, a web page likethe one that is illustrated in FIG. 12 is presented. As illustrated inFIG. 12, for each series of search history records (record set), thefirst specified search criteria in the record set (the search criteriaincluded in the record flagged “1” in the record set), time when thesearch was executed, and a link to the details of the record set aretabulated and shown (a list of search criteria (keywords); Z). In thistable, when a “Ref. to a Series of Search Results” link is clicked, aseries of search results for the record set is displayed (FIG. 13). If“my past search history” is referenced, it is preferable to attach a“Delete” link to each entry line of search history in the table shown inFIG. 13, thus enabling the user to delete his or her search historyrecords.

The second user references search history in this way (S14) for contentsearch reference. While history search is illustrated in this example,it is also possible to request the intermediate server to present searchhistory records of a specific user (for example, the first user) towhich, for example, the second user has attached a bookmark. It is alsopossible to enter keywords as conditions of a search and request theintermediate server to present search history records including commentakin to the keywords.

When the second user issues a request to retrieve content (S15), takingadvantage of the search history records of another user, for example,the first user, the intermediate server 3 retrieves the content onbehalf of the user (S16), transfers the content retrieved from thecentral server 1 to the second user (S17), and charges the second userfor the content (S18). At the same time, the central server 1 notifiesthe intermediate server 3 of the charge for the content (S19).

Then, the intermediate server 3 credits the registrant (first user) witha reward for use of that search history record, reference to whichoccasioned the second user to get content. The credit is applied in sucha way as to discount the charges owed by the first user (S20). Thesystem for funding rewards such as discounts may preferably varyaccording to whether or not the intermediate server 3 and the contentdatabase 11 are operated by the same entity. More specifically, when theintermediate server 3 and the content database 11 are operated by asingle corporation, the estimated reward value can be divided by theestimated value of content to be sold to calculate a markup value forthe content. Then when determining a price per content article, thismarkup price is included to ensure that the venture is profitable (asthe charge for content that the intermediate server is notified from thecentral server in the step S12). If the intermediate server 3 and thecontent database 11 are operated by separate companies or as separateconcerns, the price per content article to be distributed (the pricethat the user is charged at step S11) may be determined by including amarkup calculated by dividing the estimated cost of rewards to beoffered by the estimated amount of content articles to be sold.Alternatively, at step S20, the service provider running theintermediate server 3 may require that the content distributor bear theburden of rewards. It is preferable that the charges assessed by thecontent distributor reflect the quantity of the content distributed.

Furthermore, at step S14, the second user is provided an opportunity toevaluate the search history records that he or she referenced. Theevaluation points for a record are added up and retained in associationwith the record. The evaluation points are used to, for example, arrangethe order of presentation of search history records according to theevaluation points awarded the content.

In the example used to illustrate the embodiment, the user selectscontent directly from the search results included in the referencedsearch history of a registrant and issues a request to get the content.It is also possible that the user references the search history of aregistrant and attempts a further search through history records,modifying the search criteria and, based on the result of the furthersearch, the user issues a request for content. In such a case, it isdetermined whether or not the user relied on the first search historywhen selecting content by comparing the of search results returned bythe search subsequent to accessing of the first search history with theresults included in the first search history (how many correspondingsearch results are included) or by comparing search criteria returned bythe later search to those included in the first search history (how manycorresponding keywords are included). Specifically, if a certainpercentage of corresponding search results or search criteria areincluded, the intermediate server determines that the first searchhistory was used when content was selected and therefore executes thestep of rewarding the registrant of the first search history.

If the user chooses a search range other than “my search history only”on the GUI window shown in FIG. 11, that is, searching records of searchhistory of someone else as well, a “Past Search by Other Searchers” link(Q) is attached to each entry item of a past search results table; itsdisplay is illustrated in FIG. 14. When the user clicks this link for asearch result entry, a list of registrants of search history recordsrelated to that search result item is displayed (FIG. 15). Preferably,the registrants in this list can be arranged according to predeterminedconditions. For example, the registrants in the list shown in FIG. 15are arranged in the order of the number of hits (the count of the searchhistory records appropriate for the category).

When the user clicks an entry (of a registrant of history searchrecords), information about the search history records of the registrantis displayed (FIG. 16 (R)). In the list table (R) shown in FIG. 16, ifcomment accompanies an entry, its pop-up window (S) is shown when themouse cursor is positioned at the entry. Furthermore, the intermediateserver 3 makes and displays a “comment list” of the registrant byrequest (FIG. 17). Each comment in the comment list has a link to a webpage on which a series of search history records related to the commentis displayed. This allows users that share a same interest tocommunicate with each other, and can even provide support forminginterest groups or clubs over the network.

[Advantage Offering and Determining Its Limit]

Examples rewards to be given to the registrant (first user) of thereferenced record in the step S 20 will be explained below. A reward maybe in the form of, for example, virtual gift certificates (or discounts)that can be used when that user later purchases content, or in the formof a direct cash payment to the user. Preferably, the discount or theamount of money should be determined as follows.

The discount or the amount of money as reward should be adjustedaccording to the elapsed time between the release of a content articleand the time when the second user retrieves the content as a result ofreferencing the search history of the first user. Generally, content ismore likely to be promoted through frequent advertisement or the likeimmediately after its release. However, as time passes after the releaseof the content, the content loses freshness and may be forgotten, suchthat opportunities for obtaining the content become more limited.Meanwhile, experience shows that some content, such as, for example, anold movie can be revived and become a hit because of nostalgia for thecontent and because the elapse of time has made it fresh for a new groupof people. Therefore, it is preferable to adjust the value of thediscount or cash reward according to a rule that the older the contentarticle, the greater will be the reward. The frequency of access to thecontent is also taken into consideration. For a content article forwhich a certain period has passed after its release, for example, thereward system may be arranged such that when the count of occurrences ofaccess to the content for a predetermined period becomes greater than apredetermined value, a cash reward is paid as an advertising cost to theregistrant of search history records concerning the content, separatelyfrom step S 20. However, the size of this reward should be limitedbecause too great a reward would be undesirable. For example, a limit asis shown in FIG. 18A can be set and the reward can be controlled not toexceed the limit. Alternatively, the reward value may be set to follow acurve that gradually comes close to the limit as is shown in FIG. 18B.It is also advisable to set the above amount at “0” or a small constantvalue during a certain period after the release of a content article.

For content such as news, conversely, the older the content, the lowerwill be its value, and it may be necessary to decrease the price of thecontent. Therefore, it is necessary to consider the price of the contentwhen determining the size of the reward to be given to the registrant ofthe referenced record in step S20.

The size of a cash reward to be awarded at step S20 should be determineddepending on how much the search history contributed to increasing theopportunities to distribute content (in other words, according to thevalue of the search history) and the price of the content when it isdistributed. The value of the search history is determined, according tohow old the related content is (the days that have passed after itsrelease) and the rate of increase of access to the search history overtime.

Because it is not desirable that the sum total of the discounts orawards to be given to the registrant of the referenced record exceed thecharge for the content when many users referenced the search historyrecord the total should preferably be limited. To ensure that such alimit is established, the cumulative total of the discounts or awards tobe given to the registrant of the referenced search history recordbecause other users referenced the record should be recorded as part ofthe search history record exemplified in FIG. 2. Prior to the executionof step S20, the intermediate server 3 identifies the referenced searchhistory record and refers to the cumulative total included in therecord. If the cumulative total exceeds a predetermined amount, theintermediate server does not execute step S20. If not, the serverexecutes step S20 and adds the monetary value or equivalent given to beawarded to the registrant to the cumulative total.

[Special Users]

The size of a cash reward to be given to the registrant of thereferenced search history record depends on the value of the record asdescribed above, and moreover, the value of the record also depends onhow other users view the record as well as the contents of the record.For example, when a reliable evaluation is established for searchhistory records of a user, other users can expect to search out desiredcontent more quickly by reference to these records, and, therefore, suchpotential utility of the records increases the commercial value of therecords. As another example, search history records of a famous personmay attract a great deal of attention. In view hereof, the commercialvalue of such records is regarded as high.

Therefore, users whose search history records have a relatively highcommercial value should be distinguished as “special users” by attachinga “special user flag” to their records. Arrangement can be made forusing these records as follows. When a user executes the step S14 forsearch reference, search results included in these records with the“special user flag” are not rendered to the user in the usual process.These search results are only provided to users who agree to pay anextra fee for referencing those results.

[Coping with Cancellation]

According to the above-described operation procedure, when a contentarticle is sold or distributed to a user, a reward such as a discount isgiven to the registrant of the record referenced by the user whoeventually selected the content. However, it is necessary to allow forinstances when users cancel content purchases. The following arrangementmay preferably cope with such situations. When a user chooses to buy acontent article that was discovered as a result of reference to a searchhistory record of someone else at step S15, the intermediate serverpresents a conformation message to the user; such as, for example,“Because you referenced a search history, this purchase agreement cannotbe canceled. Do you agree?” Distribute the content in the steps S16 andS17 only when the user agrees.

[Using Authentication Information]

It is preferable that the user (registrant) to which advantage is givenin the step S20 can be reliably authenticated. Therefore, userauthenticating arrangements are made such that the central server 1 (orintermediate server 3) has one of a pair of keys and a user has theother key of the pair, wherein the pair of keys is unique to each user,and that user key data is set in the user's search history record asauthentication information. By means of this arrangement, using a falsename to earn rewards is prevented. For example, the central server 1 canexecute the following authentication procedure before rewarding aregistrant. When the first user purchases a content article (or the usersearch history record is created), the central server 1 generates keydata to be attached to the record of the first user. The central serverretains the key data linked with the first user identifying informationand sends the key data to the first user's terminal device. The firstuser's terminal device encrypts the key data with the first user'sprivate key which has been assigned beforehand and sends the encryptedkey data to the intermediate server 3. The intermediate server 3incorporates the encrypted key data into the user's search historyrecord, thus retaining it. Thereafter, when the second user referencesthe search history record of the first user at step S15, the encryptedkey data included in the record is further encrypted with the seconduser's private key and sent to the central server 1. The central server1 decrypts the double encrypted key data using the public keycorresponding to the second user's private key (the public key can beobtained from a public key server or the like which is not shown). Thecentral server 1 decrypts the encrypted key data with the public key ofthe first user, thereby reproducing the key data. The central server 1compares the thus obtained key data with the key data retained by it,which was sent to the first user, and determines whether matchingoccurs. When matching occurs, the step of rewarding the first user isexecuted.

[Attaching Additional Information]

In the described preferred embodiment, comments are included in a searchhistory record and GUI windows are configured so that comments can beshown (FIG. 16 (S)). However, it is preferable to allow users to searchcomments. For example, if a “my favorite” tag is attached to a comment,a search for search history records with the “my favorite” tag can beperformed and this is preferable. In this case, it is convenient forsearchers that a list of keywords is provided. It is preferable to allowusers to select any keyword from the list of predetermined keywords (aswell as enter free sentences) when entering comment.

It is also preferable to allow users to attach a “bookmark” tag to asearch history record that the user once referenced during searchoperation. Specifically, the search history record exemplified in FIG. 2includes information for identifying the user who attached a “bookmark”tag to it (bookmark placer information). The attacher of the bookmark isidentified by this bookmark placer information. This “bookmark” tag isused in a search process and a user can quickly search for the searchhistory records to which the user has attached a “bookmark” tag.

While comments and “bookmark” tags are used to facilitate the searchprocess in the above example, the registrant of search history recordscan use them to arrange his or her own records. Although comments and“bookmark” tags were described above, a search history record mayinclude other attribute information that can facilitate the searchprocess.

[Application of the Invention to a Patent Search System]

In the information search system of the present preferred embodiment,the intermediate server 3 executes searches and the central server 1only distributes the searched out content; that is, the central server 1is not engaged in the processes of receiving conditions of a search andsearching for content (an object to search). Attaching the intermediateserver 3 to a corporate intra-net makes it possible to searchinformation on the central server 1 without transmitting keywords of asearch over an external network.

This advantage is useful for application such as pattern informationsearches in which it is undesirable that recent developments andtechnical achievements be disclosed to other corporations.

1. An intermediate server, comprising: a providing unit that searchesinformation in a central server based on a search request from a user onbehalf of a user terminal and provides a search result to the user; aretaining unit that retains the search result as a user search historybeing connected with the search request to specialize in a field ofinformation based on the user's interest; an index management unit thatgenerates an index information in the specialized field of informationfor searching the information in the central server; and a storing unitthat stores the index information, wherein the user search history isshared with a plurality of users and is used for supporting a usersearch operation, and the index management unit updates the indexinformation when the information in the central server is updated,wherein, for the intermediate server, reference information includingthe field of information that the intermediate server specializes in andidentification of the intermediate server is registered in the centralserver, the central server identifying, upon receipt of new information,the intermediate server associated with a field of the received newinformation, the central server sending update information to theidentified intermediate server to notify the intermediate server of thereceipt of the new information, and the index management unit containedin each of the intermediate server updating the index informationaccording to the update information sent from the central server.
 2. Aninformation search method, comprising: receiving a search request from auser; searching information in a central server based on the searchrequest; providing a search result to the user; and retaining the searchresult as a user search history being connected with the search requestat one of a plurality of intermediate servers that specialize in a fieldof information based on the user's interest, each of the plurality ofintermediate servers comprising an index management unit that generatesan index information of the information and a storing unit that storesthe index information, the index management unit updating the indexinformation when the information in the central server is updated,wherein the search result and a result of past searches are storedtogether at least one of the plurality of intermediate servers, and theuser search history is shared with a plurality of users and is used forsupporting a user search operation, wherein, for each of theintermediate servers, reference information including the field ofinformation that the intermediate server specializes in andidentification of the intermediate server is registered in the centralserver, the central server identifying, upon receipt of new information,one of the intermediate servers associated with a field of the receivednew information, the central server sending update information to theidentified one of the intermediate servers to notify the identified oneof the intermediate servers of the receipt of the new information, andthe index management unit contained in each of the intermediate serversupdating the index information according to the update information sentfrom the central server.
 3. The information search method according toclaim 2, wherein when the search request is executed by making referenceto the user search history of another user, a process of rewarding tothe user is executed.
 4. An information search system for searchinginformation, comprising: a central server having the information; a userterminal operated by a user;and a plurality of intermediate serverslocated between the central server and the user terminal, each of theplurality of the intermediate servers further comprising: a providingunit that searches the information in the central server based on asearch request from the user on behalf of the user terminal and providesa search result to the user terminal; a retaining unit that retains thesearch result as a user search history being connected with the searchrequest, wherein the user search history is shared with a plurality ofusers and is used for supporting a user search operation, wherein eachof the plurality of intermediate servers specializes in a field ofinformation based on a user's interest; an index management unit thatgenerates an index information of the information; and a storing unitthat stores the index information, the index management unit updatingthe index information when the information in the central server isupdated, wherein, for each of the intermediate servers, referenceinformation including the field of information that the intermediateserver specializes in and identification of the intermediate server isregistered in the central server, the central server identifying, uponreceipt of new information, one of the intermediate servers associatedwith a field of the received new information, the central server sendingupdate information to the identified one of the intermediate servers tonotify the identified one of the intermediate servers of the receipt ofthe new information, and the index management unit contained in each ofthe intermediate servers updates the index information according to theupdate information sent from the central server.
 5. The informationsearch system according to claim 4, wherein the search result and aresult of past searches are stored together.
 6. The information searchsystem according to claim 4 wherein at least one of the plurality ofintermediate servers retains retaining information about the field ofspecialization of another intermediate server on the retaining unit. 7.The information search system according to claim 6, wherein one of theplurality of intermediate servers further comprises a searching unitthat searches the other intermediate server based on a field of key datawhich is attached to the user search history and provides the searchresult to the user terminal.
 8. The information search system accordingto claim 4, wherein, when the search request is executed by makingreference to the user search history of another user, at least one ofthe intermediate servers executes a process of rewarding to the user. 9.The information search system according to claim 8, wherein a reward isan amount of money, and no reward is given when the reward exceeds apredetermined amount of money.
 10. The information search systemaccording to claim 4, wherein the user search history has informationabout time when the information is searched, and the user search historyis deleted after a predetermined period of the time has passed.
 11. Theinformation search system according to claim 4, wherein the user searchhistory includes an evaluation information by another user who refersthe user search history, and the evaluation information is used for aprocess of presenting the user search history.
 12. The informationsearch system according to claim 4, wherein at least one of theintermediate servers is determined by a user based on the search requestand the user terminal retains an identifier of the at least onedetermined intermediate server.
 13. The information search systemaccording to claim 4, wherein each of the plurality of intermediateservers searches the index information stored in a storing unit forsearching the information based on the search request.
 14. A storagemedium readable by a computer, the storage medium storing a program ofinstructions executable by the computer to perform a function forsearching information based on a search request from a user, thefunction comprising: receiving the search request from the user;searching the information in a central server based on the searchrequest; providing a search result to the user; and retaining the searchrequest as a user search history being connected with the search requestat one of a plurality of intermediate servers that specialize in a fieldof information based on the user's interest, each of the plurality ofintermediate servers comprising an index management unit that generatesan index information of the information and a storing unit that storesthe index information, the index management unit updating the indexinformation when the information in the central server is updated,wherein the search result and the results of past searches are storedtogether at least one of the plurality of intermediate servers, and theuser search history is shared with a plurality of users and is used forsupporting a user search operation, wherein, for each of theintermediate servers, reference information including the field ofinformation that the intermediate server specializes in andidentification of the intermediate server is registered in the centralserver, the central server identifying, upon receipt of new information,one of the intermediate servers associated with a field of the receivednew information, the central server sending update information to theidentified one of the intermediate servers to notify the identified oneof the intermediate servers of the receipt of the new information, andthe index management unit contained in each of the intermediate serversupdating the index information according to the update information sentfrom the central server.
 15. The information search method according toclaim 3, wherein a reward is an amount of money, and no reward is givenwhen the reward exceeds a predetermined amount of money.